Floor structure



March 5, 1963 A. M. MUIR 3,080,021

FLOOR STRUCTURE Filed June 20, 1960 4 Sheets-Sheet 2 F1. '.2. 4 F1 g'FJ. g. E.

I INVENTOR ALAN M. MUIR ATTORNEYS.

March 5,; 1963 A. M. MUIR 3,080,021

FLOOR STRUCTURE Filed June 20, 1960 4 Sheets-Sheet 4 my i 10/ w v Tar g.Jl.

INVENTOR ALAN M.MU|R

BYMV/ ATTORNEYS.

3,62%,621 FLGGR STRUCTURE Alan M. Muir, Qshawa, Ontario, Canada,assignor to R. D. Werner 0. (Canada) Limited, Ushawa, Ontario,

Canada, a company of Canada I Filed June 29, 196i Ser. No. 37,287 Claimspriority, application Canada June 25, 1959 Claims. (Ql. 189-34) Thisinvention relates to a novel combination of shaped sections which isparticularly advantageous for use as a door structure which may be usedin connection with the cargo-carrying space of a transportation vehiclesuch as a truck or the like.

There are a number of characteristics which it is advantageous to obtainwhen designing such a flooring structure. One criterion which, ifpossible, should be satisfied is that of allowing replacement ofindividual floor planks, when such become damaged without dismantlingthe whole floor structure. Another is that of so designing the elementsthat a major portion of the work of assembly can take place from theupper surface of the floor and, preferably under conditions wherein itis possible to assemble substantially the whole of the floor prior toits being placed in position on the truck chassis.

hired grates Fatent It is also important to provide an arrangement suchthat the various floor elements can quickly, and accurately, be fastenedtogether by more or less unskilled labour. An important factor inobtaining the last-mentioned desirable characteristics is so to designthe plank-holding elements as to require only the minimum number ofhole-s to be drilled for fastening devices such as bolts, through eitherthe planks themselves or the cross bearers upon which the plwks rest;this latter characteristic is in itself desirable because of thestronger structure it yields due to the absence of holes in the flanges,webs etc. of the various structural floor elements. Due to thesubstantial amounts of water, corrosion-producing dirt and chemicalswhich are splashed upwardly from the road surface onto the bottom of thetruck floor structure, it is most desirable to provide an arrangement inwhich the fastening elements maintaining the floor planks in positioncan be substantially wholly shielded and thus protected from contactwith corrosion-producing substances and the cargo protected from damagein wet weather. At the same time it is in many cases important toprovide a substantially smooth floor surface on which the cargo willrest unimpeded by projecting, or exposed fastening elements such as nutsor bolt heads. Finally, it is desirable to arrange a flooring systemwhich is sufliciently flexible so that planks of ditferentcross-section, such as for example those designed to give a fiat surfacefor dry cargo, and others which give a corrugated surface particularlyadapted for refrigerated space, can be used interchangeably not onlywhen the floor is originally assembled but afterwards as ell so that ifdesired the floor surface can be changed so as to be more suitable for adifferent purpose.

A number of prior attempts have been made to devise a system of extrudedor otherwise shaped elements which would produce a truck floor meetingcertain specified design criteria. While many of these yield one or moreof the desirable characteristics mentioned above none, so far as I amaware, are adapted to possess them all and still be reasonablyeconomical and flexible enough to use on any substantial commercialscale. Many of these prior designs involve the drilling of holes forfastening elements through either the extruded floor sectionsthemselves, the cross bearers on which they rest, or both. Moreover,such fastening elements are usually so positioned as to require them tobe manipulated from both the upper and lower surfaces of the door and atleast one part of the elements Patented Mar. 5,. 1963 is often exposedon the bottom side of the truck and therefore subjected to the corrosiveaction of dirt and chemicals splashed upwardly from the road. In otherdesigns it is difficult, if not impossible, to remove and replace onedamaged plank without dismantling substantially the whole of the floorstructure and at the same time being forced to conduct a great deal ofthe Work on the underside of the truck. Finally, many of the priordesigns of which I am aware are of such a nature as to result in asingle, specialised type of truck floor and the construction is suchthat it cannot be applied to a range of different floor types designedfor a variety of purposes but which have sufficient structure in commonto permit interchangeability of planks and similar, if not identical,fastening elements. So far as I am aware none of these prior designshave, for instance, permitted use of a variety of non-skid surfaces(which are added after the basic extrusion or similar shaping has beenmade) without at the same time failing to give one or more of thedesirable characteristics mentioned above.

It is accordingly an object of this invention to provide a combinationof shaped elements which can be formed into an economical,'easilyassembled floor structure wherein any one of a variety of types of plankmembers can be used interchangeably. It is also an object of myinvention to provide a quickly assembled floor structure resulting in asubstantial saving of labour over prior structures and requiring only aminimum number of holes to be drilled when the floor is being assembledand placed in position on the truck chassis. It is a further object ofmy invention to provide a substantially weatherproof floor structure forprotection of a cargo and wherein the fastening elements are shieldedfrom contact with corrosion-producing substances splashed upwardly fromthe road. It is a further object of my invention to provide a floorstructure which in at least one embodiment thereof can be arranged sothat no fastening elements whatever are exposed on the upper,cargo-supporting surface of the floor.

' I have found that a floor structure having the advantageouscharacteristics listed above can be obtained by providing cross bearermembers having a vertical Web and flanges extending outwardly therefromon each side 1 the web at its top, these flanges providing an upperhorizontal bearing surface on which the shaped plank members rest. Theseplank members extend between the cross bearers, and have vertical sidemembers located along each edge (longitudinal) thereof.

In the side members of each plank, located intermediate the top andbottom of each plank, are outwardly extending horizontal flanges sopositioned that when two planks are resting on the bearing surface, thehorizontal flanges on mutually facing side members of adjacent planksextend toward, and are in registry with each other. My invention alsorequires the use of clam-ping pieces which have a central horizontalpart adapted to extend transyersely of, and engage with, the bearingsurface. The clamping pieces have lower and upper channels adapted (whenthe clamps are loose) for slidable, non-rotatable engagement with theflanges of the cross bearers and one end of a fastening element,respectively. The fastening element may conveniently be a square orhexagonal headed bolt, the head sliding in the upper channel of theclamping piece. The body of the fastening element extends upwardly fromthe clamping piece between the mutually facing horizontal flanges ofadjacent planks. Means cooperating with the other end of the fasteningelement, such as for example a washer and nut, bear against the uppersurface of the horizontal flanges so that the planks are drawndownwardly into tight engagement with the bearing surface, and theclamping pieces are simultaneously drawn upward so that the lowerchannel thereof securely grips the flanges of the cross bearers. A coverplate may be so arranged on the upper surface of the floor as to extendbetween adjacent plank pieces so as completely to enclose the channelformed between adjacent planks by the horizontal flanges along each edgethereof, within which channel the fastening elements are exposed. Theshaped elements such as the plank mem-' bers, cover plate and crossbearer members are prefa erably extruded members, although any suitableshaping or'forming process such as rolling, may be used within the scopeof the present invention to produce the required (structural) floorelements.

The preferred form of said plank members comprises an upper horizontalload carrying surface having supporting leg members extending from saidload carrying surface to the horizontal bearing surface of thecrossbearer members. member especially suitable for refrigerated freightflooring'comprises a corrugated cross-section of square-wave shae.

T he invention will now be described with reference to the attachedfigures of drawings in which FIGURE 1 is a sectional view, partly brokenaway, of the complete flooring assembly made inaccordance with theinvention;

FlGURE 2 is a cross-sectional view of a clamping I Ce;

FIGU'RE 3 is a cross-sectional view of an auxiliary clamping plate,which can conveniently also serve as a retainer clip;-

FIGURE 4 is a cross-sectional viewof a cover plate which can be used inconstructing conventional flat FIGURES is a perspective view of a clampassembly comprising a clamping piece, a bolt inserted in the upperchannel thereof, and a retaining clip slipped over the bolt and theclamping piece so as to maintain the former in position therein; 7

FIGURE 6 is a cross-sectional view.- of one particular type ofplankmember-which, when used with a cover plate such'asissliown inFIGURE 4, yields a flat floor free from exposed fastening elements;

FIGURE 7 is a cross-section through the floor assembly, taken-betweencross bearer members;

FIGURE'E-is a cross-section through the floor assembly taken at a crossbearer member;

FIGURE 9 is a cross-sectional end view illustrating a "terminalcross-bearer member having'an elongated web adapted to cover the openends of the-plank members;

FIGURE 10 is a cross-sectional view of a further type of plank memberuseful in refrigerated flooring systems; FIGURE 11 is a cross-sectionthrough'a floor assembly composed of the plank members of FIGURE 10.

Referring new to FIGURE 1, the floor structure according'to theinvention comprises cross bearer member ltl having' a vertical web 11and transversely extending flanges 12 and 13 extending outwardly, in ahorizontal direction, at the top of the web 11. The upper surface of theflanges 12 and 13 provides a bearing surface generally indicated at 14.In the embodiment ofthe lnvention shown in the drawings the major partof the floor surface comprises plank members 15 having a horizontalportion 16 and downwardly extending side members 17 along each edgethereof. Depending upon the width of the particular plank 15 adopted itmay be necessary to have additional leg members 18 extending downwardlyfromv the horizontal portion 16 intermediate the side members 17, asshown. The leg members 18 themselves preferably comprise a verticalflange 19 and feetZG, but may. comprise any suitable shape consistentwith good structuraldesign. Similarly, the side members 17 mayconveniently. be given inwardly, extendingfeet members planks extendtoward, and are coplanar with, each other as illustrated. As will beexplained in more detail below, in accordance with a preferredembodiment of the invention additional upwardly turned flanges 27 may belocated on each of the side members 17 of the plank 15;

Moreover, to facilitate a tight and neat fit of the cover plate which isdesigned to bridge the gap between adjacent planks, the upper surface ofthe latter, along each edge thereof, is recessed as shown at 28.Although only a a single intermediate leg member 25 has been shown in Afurther preferred shape of plank N FIGURE 6 for the sake of clarity, itwill be understood that any number of leg members of a suitablestructural shape are contemplated within the scope of this inventiondepending on the intended use of the plank members. Similarly the metalthickness of the cross bearer members 10 and planks 15 may varydepending on the intended load requirement, especially if extrudedelements are used.

As best shown in FIGURES l and 8, a clamping piece 30, having a crosssection such as is shown in FIGURE 2, is positioned on the flanges 12and 13 of the cross bearer 10. Clamping piece 30' itself comprises acentral horizontal portion 31 the bottom side 32 of which is designed tobe in contact with thebearing surface 14. Ateach edge of the clampingpiece 30 are located L-shaped flanges 33 which extend downwardly andthence inwardly to define a lower channel generally represented at 34.On the upper surface of the clamping piece are located further flangemembers 35 which serve to define an upper channel 36'. As is apparentfrom FIGURE 1, the lower channel accommodates the flanges 1 2 and 13 ofthe cross bearer and permits clamping piece 30 to have slidable butnon-rotatable engagement therewith; The upper channel is adapted toaccommodate slidably, but not rotatably, one end of a fastening element,such as for example a square or hexagonal bolt head. After the bolt 37is insertedso that its head 37a is accommodated in the channel. 36 andthe shank of the bolt extends upwardly from the clamping piece 30, aretaining clip-generally indicated at 38, having a centrally locatedaperture 39, may he slipped down over the shank of the bolt 3'7 so thatthe sides 4% of the retaining clip grip the ends of the clamping piece.longitudinally of the upper channel 36. To facilitate. this; operationthe sides of the U-shaped retaining J clip'may be designed that theytaper inwardly towards each other by a very slight amount with theresult that when they are initially spreadand slipped over the clampingpiece 30, they will tend to snap into position and remain there duringfurther handling. The clamping assembly thus formed, shown in FIUURE 5and therein generally represented at 50, consists of three parts, theclamping. piece 39, the bolt 37 and the retaining clip 38. This assemblyis designed'to be placed on the cross bearers 1i and moved along thebearing surface 14 to the required position, as will be explainedin moredetail below. The bolt shank 37 may also serve as .a location gauge forspacing planks 15 while the floor structure is being assembled. 7

Referring now to FIGURE 8 the details of the joint between two adjacentplanks wil11be described. As there shown, the planks 15 are positionedon the cross bearer ltiso that; the mutually facing ends. of thehorizontal flanges 26 are spaced'apart a distance just suificient topermit the, shank of bolt 37 to extend upwardly therebetween. When theclamping assemblies 50 on each of the cross bearers ltlsupporting theadjacent planks 15 have been positioned in this way, a lock nut 51, orsimilar; suitable fastener, preferably in conjunction with some type ofa washer or other pressure-distributing plate, is screwed onto the shankof the bolt 37 and tightened downwardly so as to raise the clampingpiece 30 in such a way that the flanges 12 and 13 of the cross bearerare securely gripped within the lower channel 34 and, at the same time,the action of the nut on the horizontal flanges 26 forces the planks 15downwardly into tight engagement with the bearing surface 14. As isapparent from FIGURES 1 and 8 this whole particular operation can becompleted from the top surface of the floor and no part of it requiresmanipulation of fastening elements from beneath the cross bearers 10.

In the preferred embodiment of the invention shown in the drawings, theplanks 15 are provided with upwardly turned flanges 27, in addition tothe horizontal flanges 26. Interposed between the nut 51 and the uppersurface of the horizontal flanges 26 is an auxiliary clamping plate 52having a generally U-shaped cross-section comprising a flat lowerportion 53, side members 54 and downwardly turned flanges 55 at the topof each of the side members. These flanges are so positioned as toengage with the upwardly turned flanges 27 of the planks 15. As aresult, when the nut 51 is tightened, the downward pressure on the plank15 is transmitted through both the horizontal flanges 26 and theupwardly turned flanges 27. As best shown in FIGURE 8 I have also foundit advantageous from the point of view of economy and ease in assembly,to use a member of the same cross section for both the auxiliaryclamping plate 52 and the retaining clip 38. When this is done, theretaining clip 38 is provided with upwardly turned flanges 56 at eachside on the bottom thereof identical with the downwardly turned flanges55 at each side of the top of the auxiliary clamping plate.

After the nuts 51 have been tightened so that the planks 15 are heldfirmly in position on the cross bearers there will, of course, be anexposed channel between each of the planks within which the fasteningelements are located. In most cases it is, of course, desirable thatthis channel be covered and that a substantially flat smooth surface beprovided. For this purpose a cover plate 60 having a cross section suchas is shown in FIGURE 4 is placed in the channel so that it traversesthe gap between the mutually facing edges of adjacent planks 15. If, asis the case with the plank cross section shown in FIGURES 1 and 6, theupper corners of the planks are recessed as at 28, the ends of the coverplate may be designed to fit down into the recess so that the topsurface of the plate is parallel with the top surface of the plank 15.As shown in FIGURES 4, 7 and 8, the cover plate 60 is preferablyprovided with a centrally located channel 61 on the bottom thereofi. Theinterior mutually facing sides of the channel are provided with grooves62. These grooves can be designed 7 so as to grip the threads of a bolt,as shown in FIG- URE 7. In regions of the floor between the crossbearers 10 bolts 63, preferably in conjunction with some type of awasher or other pressure-distributing plate, are inserted upwardlybetween the horizontal flanges 26, and rotated so that the threads ofthe bolts 63 engage with the corrugated channel 61. A suitable lockingdevice (not shown) may be operatively associated with bolts 63 to ensureproper engagement with cover plate 60. In the embodiment shown in FIGURE7 the washer is merely another length of the same cross section as isused for both the auxiliary clamping plate and retaining clip. As thebolt 63 is rotated the cover plate 66* is drawn down into position andretained there.

Assembly of a complete floor structure in accordance with the inventionis follows. After the cross bearers 10 are placed in position, the plank15 located at either of the extreme outer sides of the floor is attachedto the cross bearers by conventional fastening means, such as forexample bolts and nuts, extending through the feet 21 and the flanges atthe top of the cross bearers.

This operation requires drilling and will usually involve somemanipulation of fastening elements on the undersurface of the floor.Work of this type is, however, reduced to a minimum since it is only theoutside planks at each edge of the floor that are fastened to the crossbearers in this manner. Having placed one of the edge planks inposition, the required number of clamping assemblies 56 shown in FIGURE5 can then be placed on each of the cross bearers and moved therealongto their appropriate final position which, of course, depends on thewidth of the particular planks being used. The first clamping assemblyon each of the cross bearers is moved into position adjacent the side ofthe edge plank. The second plank which is to be immediately adjacent toit is then laid across the cross bearers and moved transversely intoclamping position. A washer, or alternatively an auxiliary clampingplate 52, is then placed over the bolt so that it rests on the uppersurface of the horizontal flanges 26. A nut is then screwed onto thebolt and driven tight. This operation may be repeated for eachsucceeding plank and, following the positioning of the edge plank at theother extreme edge of the'floor, further conventional fastening elementsmay be used to attach the plank to the cross bearers in a manner similarto that of the opposite edge plank. A further preferred method ofassembling the floor structure of the present invention is to firstarrange and hold all of the planks and clam-ping assemblies in positionand then tighten all of nuts at the same time. Following theseoperations the cover plates 69 may be laid in each of the channelsbetween the planks and fastened there securely, such as for example bybolts 63 engaging with the grooves 62 of the channel 61, shown in FIGURE7. These nuts are, of course, positioned along the planks at pointsbetween the cross bearers 1t) and this panticular operation must becompleted from the underside of the floor.

It will be noted that a flooring arrangement has been provided in whichthe only drilling operation required is that in which the planks at theextreme edges of the floor are attached to the cross bearers; even thisamount of. drilling would be avoided where vertical side members alongthe edge of the floor structure are designed to engage with the edgeplanks and maintain them rigid ly in position against the crossbearer-s. The intermediate planks are securely clamped to the crossbearers by a clamping assembly to which access is possible from the topof the floor and for which no bolt holes must be drilled through eitherthe planks or the cross bearers. Moreover, the major part of the floorassembly operations can be completed from the top surface of the floorand it is only the fastening, by conventional means, of the edge planks,and the cover plates, that requires access to the bottom surface of thefloor.

Variations in the design of the outer plank members or outercross-bearer members may be necessary in order to provide a completedfloor assembly unit. FIGURE 9 illustrates such a variation in the designof the terminal cross-bearer members 10, which will cover up the openfront and rear ends of plank members 15. The crossbearer member of thisembodiment includes side member 57 and an upper extension 58 which isadopted to cover up the open ends of plank 15, thus providing a morefinished and substantially weather-proof front and/ or rear end of theflooring system. The horizontal bearing flanges 12 and 13 extendoutwardly on each side of web 11 which is connected by connecting member59 to side member 57 intermediate the top and bottom thereof. The planks1'5 and clamping members 39 rest upon the upper surface of flanges 12and 13, and the L- shaped flanges 33 of clamping piece 39 engage theterminal edges of flanges 12 and 13 as illustrated in FIG URE 9.Retaining clip 38 and clamping plate 52 are arranged with bolt 37 andnut 51 so as to securely grip and hold the horizontal flanges 25 ofplank members 15 in position as described in detail hereinabove.

It may also be necessary to provide supplementary plank elements at thetwo outermost longitudinal edges of the plank members so as to provide ameans of securing the floor assembly in its required location. Forexample, if the floor assembly of the present invention is to be usedwith a flat platform and stake type of truck, an outer supplementaryplank member could usefully be employed which would engage with thevertical side member of the outermost plank member in a manner describedhereinabove, and then extend downwardly across the end of the crossbearer members and extends inwardly to engage with the lower portions ofthe crossbearer members. A similar supplementary plank member could beemployed in floor constructions of van body type trucks with theexception that the supplementary plank member instead of Wrapping aroundthe end of the side bearer members, would be secured to the side wallsof the truck by conventional means.

FIGURES 1 to 9 of the dravw'ngs show only one general type of plankcross-section and cover plate, i.e. that giving a flat conventionalfloor surface commonly used for dry cargo. It will be apparent to thoseskilled in the art that numerous plank sections could :be used. Forexample, plank members having a corrugated cross-section of square-waveshape would be particularly useful for a floor in a refrigerated storageor freight space.

Such an embodiment is illustrated in FIGURES l and ll of the drawings.The cross-section of the plank members is-illustrated in FIGURE 10 andis composed of a series of rectangular or square components withcomponents 67 providing the upper load carrying surface and components69 engaging with the upper horizontal bearing surface of cross-bearermembers 10. Cornponents 67 and 69 are connected together by verticalsupporting components 68. The longitudinal edges of this plank memberconsists of an upwardly extending side member 70 having a flange 71extending outwardly at the top thereof, with a flange 72 extendingupwardly from flange 71, as illustrated. Horizontal flange 71corresponds to the horizontal flange 26 of the plank members illustratedin FIGURES 1 to 9, and are to be placed in an adjacent co-planarrelationship as shown in FIG- URE 11. Clamping piece 36, retaining clip38-, clamping plate 52, bolt 37 and nut 51 are then arranged asdescribed hereinbefore, with the exception that the downwardly turnedflange 55 of clamping plate 52 engage vertical flanges72, thus securingthe plank members to each other and to cross-bearer 10. A cover-plate 74may be secured over the fastening elements, as shown in FIGURE 11, andis preferably of such a design as to present an uninterrupted corrugatedfloor surface appearance. The cover-plate 74 should therefore be of aninverted U-shape having side portions 76 adapted to fit over theupwardly extending side members 70 of adjacent planks, and the lowerends of side portions 76 may be slightly turned outwardly to provide abetter fit at the junction of components 69 and 74 The coverplate 74 ispreferably provided with a centrally located channel 77 on the bottomthereof. The interior mutually facing sides of channel 77 are providedwith grooves '75 designed so as to receive and grip the threads of abolt. Cover-plate 74 may therefore be secured in position by means of abolt and retaining clip positioned inbetween cross-bearer members 10 ina manner similar to that shown in FIGURE 7. The present inventiontherefore provides an easily assembled, substantially weather prooffloor structure which can be manufactured in different structural shapesand dimensions, useful for supporting and carrying a variety of loads orcargoes. For example, a trucker could keep a supply of floor structuresof the present invention on hand and alternately use them for carryingdiiferent types of cargoes. A further application of the presentinvention would be the provision of portable floorings for temporaryshelters and. the like. Further possibilities of variation within thescope of the invention are made possible by use of the cover plates 69which can be provided with any one of various types of non-skid surfaceswell known in the art.

What I claim as my invention is:

1. A floor structure comprising: cross bearer members having a verticalweb and flanges extending outwardly therefrom on each side of the web atthe top thereof, said flanges providing an upper horizontal bearingsurface; plank members extending between the cross bearer members, saidplank members having vertical side members located along each edgethereof, the bottom of the side members being adapted to engage withsaid bearing surface, and horizontal flanges extending outwardly fromeach of said side members intermediate the top and bottom of the plank,whereby, when the planks are resting on the cross bearers the horizontalflanges on the mutually facing side members of adjacent planks extendtoward, and are coplanar with, each other; clamping pieces having acentral horizontal part adapted to extend transversely of, and engagewith, the bearing surface and also having lower and upper channels forslidable, nonrotatable engagement with the flanges of the cross bearersand one end of a fastening element, respectively, said fastening elementextending upwardly from the clamping piece between the mutuallyfacinghorizontal flanges of adjacent planks; means cooperating with theother end of said fastening element, said means'bearing against theupper surface of the said horizontaltianges whereby the planks are drawndownwardlyinto tight engagement with the bearing surface, and theclamping pieces are drawn upwardly so that the lower channel thereofgrips securely the flanges of the cross bearers.

2. A structure as claimed in claim 1 comprising a cover plate extendingbetween adjacent planks andadditional fastening means extending upwardlybetween the horizontal flanges and into the :bottom surface of the coverplate so as to retain the same in position.

3. A structure as claimed in claim 1, wherein said plank memberscomprisean upper horizontal load carrying surface having supporting leg membersextending from said load carrying surfaces to the horizontal hearingsurface of the cross-bearing members, with said horizontal flangesextending outwardly from each of said side members intermediate the topand bottom thereof.

4. A structure as claimed in claim 1, wherein said I plank members havea corrugated cross-section of squarewave shape, with said vertical sidemembers extending upwardly from the outer portions of the plank engagingsaid bearing surface and thence outwardly to form said horizontalflanges.

5. A structure as claimed in claim 4, including a cover 7 plateextending between adjacent planks and additional fastening meansextending upwardly between the horizontal flanges and into the bottomsurface of the cover plate so as to retain the same in position, saidcover plate comprising an inverted U-shaped member adapted to fit oversaid vertical side members, and having on its bottom surface a channelextending longitudinally thereof with corrugations located on theinterior vertical surfaces of the channel adapted to engage boltsextending ertically upward between the horizontal flanges.

6. The structure as claimed in claim 2, wherein the planks are providedwith a recessed portion along the top surface at each edge thereof, saidcover plate adapted to fit into said recesses so that the top thereof isin registry with the top of the plank, said cover plate having on itsbottom surface a channel'extending longitudinally thereof; andcorrugations located on the interior vertical surface of the channel;bolts extending vertically between the horizontal flanges and engagingwith saidcorrugations.

7. A structure as claimed in claim 1 comprising an invertedU-shapedretainer clip positioned on the clamping piece, the sides of the clipenclosing the ends of the 9 upper channel, said clip having an aperturein the top thereof through which the shank of the fastening elementextends, thereby retaining the same in a predetermined positionlongitudinally of the upper channel.

8. A structure as claimed in claim 3 comprising upwardly turned flangeslocated on the side members between the top thereof and the horizontalflanges, and an auxiliary U-shaped clamping plate having a bottomportion provided with an aperture through which the shank of thefastening element extends, said bot-tom portion adapted to engage withthe top of said horizontal flanges and be interposed between saidflanges and said cooperating means, the sides of the auxiliary U-shapedclamping plate extending upwardly and having at the ends thereofdownwardly turned flanges engaging with said upwardly turned flanges onthe side members.

9. A structure as claimed in claim 4, comprising vertical flangeslocated on said horizontal flanges, and an auxiliary U-shaped clampingplate having a bottom portion provided with an aperture through whichthe shank of the fastening element extends, said bottom portion adaptedto engage with the top of said horizontal flanges and be interposedbetween said flanges and said cooperating means, the side of theauxiliary U-shaped clamping plate extending upwardly and having at theends thereof downwardly turned flanges engaging with said verticalflanges.

10. A structure as claimed in claim 1, wherein the terminal cross bearermembers include vertical side members which extend upwardly to cover theopen ends of said plank members and said vertical webs of the crossbearer members are rigidly connected by connecting means, to saidvertical side members intermediate the top and bottom thereof.

11. The structure as claimed in claim 3, wherein the planks are providedwith a recessed portion along the top surface at each edge thereof, saidcover plate adapted to fit into said recesses so that the top thereof isin registry with the top of the plank, said cover plate having on itsbottom surface a channel extending longitudinally thereof; andcorrugations located on the interior vertical surface of the channel;bolts extending vertically between the horizontal flanges and engagingwith said corrugations.

12. A structure as claimed in claim 3 comprising an invented U-shapedretainer clip positioned on the clamping piece, the sides of the clipenclosing the ends of the 'upper channel, said clip having an aperturein the top thereof through which the shank of the fastening elementextends, thereby retaining the same in a predetermined positionlongitudinally of the upper channel.

13. A structure as claimed in claim 4 comprising an inverted U-shapedretainer clip positioned on the clamping piece, the sides of the clipenclosing the ends of the upper channel, said clip having an aperture inthe top thereof through which the shank of the fastening elementextends, thereby retaining the same in a predetermined positionlongitudinally of the upper channel.

14. A structure as claimed in claim 3, wherein the terminal cross bearermembers include vertical side members which extend upwardly to cover theopen ends of said plank members and said vertical Webs of the crossbearer members are rigidly connected by connecting means, to saidvertical side members intermediate the top and bottom thereof.

15. A structure as claimed in claim 4, wherein the terminal cross bearermembers include vertical side members which extend upwardly to cover theopen ends of said plank members and said vertical webs of the crossbearer members are rigidly connected by connecting means, to saidvertical side members intermediate the top and bottom thereof.

References Cited in the file of this patent FOREIGN PATENTS 662,763Great Britain Dec. 12, 1951 739,400 Great Britain Jan. 25, 1954 742,285Great Britain Dec. 21, 1955

1. A FLOOR STRUCTURE COMPRISING: CROSS BEARER MEMBERS HAVING A VERTICALWEB AND FLANGES EXTENDING OUTWARDLY THEREFROM ON EACH SIDE OF THE WEB ATTHE TOP THEREOF, SAID FLANGES PROVIDING AN UPPER HORIZONTAL BEARINGSURFACE; PLANK MEMBERS EXTENDING BETWEEN THE CROSS BEARER MEMBERS, SAIDPLANK MEMBERS HAVING VERTICAL SIDE MEMBERS LOCATED ALONG EACH EDGETHEREOF, THE BOTTOM OF THE SIDE MEMBERS BEING ADAPTED TO ENGAGE WITHSAID BEARING SURFACE, AND HORIZONTAL FLANGES EXTENDING OUTWARDLY FROMEACH OF SAID SIDE MEMBERS INTERMEDIATE THE TOP AND BOTTOM OF THE PLANK,WHEREBY, WHEN THE PLANKS ARE RESTING ON THE CROSS BEARERS THE HORIZONTALFLANGES ON THE MUTUALLY FACING SIDE MEMBERS OF ADJACENT PLANKS EXTENDTOWARD, AND ARE COPLANAR WITH, EACH OTHER; CLAMPING PIECES HAVING ACENTRAL HORIZONTAL PART ADAPTED TO EXTEND TRANSVERSELY OF, AND ENGAGEWITH, THE BEARING SURFACE AND ALSO HAVING LOWER AND UPPER CHANNELS FORSLIDABLE, NONROTATABLE ENGAGEMENT WITH THE FLANGES OF THE CROSS BEARERSAND ONE END OF A FASTENING ELEMENT, RESPECTIVELY, SAID FASTENING ELEMENTEXTENDING UPWARDLY FROM THE CLAMPING PIECE BETWEEN THE MUTUALLY FACINGHORIZONTAL FLANGES OF ADJACENT PLANKS; MEANS COOPERATING WITH THE OTHEREND OF SAID FASTENING ELEMENT, SAID MEANS BEARING AGAINST THE UPPERSURFACE OF THE SAID HORIZONTAL FLANGES WHEREBY THE PLANKS ARE DRAWNDOWNWARDLY INTO TIGHT ENGAGEMENT WITH THE BEARING SURFACE, AND THECLAMPING PIECES ARE DRAWN UPWARDLY SO THAT THE LOWER CHANNEL THEREOFGRIPS SECURELY THE FLANGES OF THE CROSS BEARERS.